This subproject is one of many research subprojects utilizing the resources provided by a Center grant funded by NIH/NCRR. The subproject and investigator (PI) may have received primary funding from another NIH source, and thus could be represented in other CRISP entries. The institution listed is for the Center, which is not necessarily the institution for the investigator. The African-American predilection for obesity is a complex problem thought to be associated with abnormal autonomic responsiveness to environmental stressors and ingestion of food. Paced breathing elicits high heart rat variability &#40;HRV&#41;and stress elicits low HRV. Low HRV after eating is a risk factor for obesity because of its association with a limitation on sympathetic modulation of insulin secretion, fat utilization and adipokineses. To meet this goal, the hypothesis will be tested in a subpopulation of healthy normotensive adolescent African-Americans, presumed to be at high risk for developing obesity in the future, and thus may exhibit low HRV during paced breathing. 25 healthy 18-19 year-old African-American male and female university students will be recruited. Subjects will be classified as a narrowband group based on HRV more than one standard deviation from the study population during paced breathing and exhibiting low capacity for sympathetic modulation of heart rate and postprandial fat utilization, by measuring the respiratory quotient. Genetic screening of genes, ADRA2B and Leptin, will also be performed.